Current-Voltage Characteristics in Superconducting Bi-2212 Tape Prepared by

                                                          PAIR Process



                               A. Yamasaki,1  T. Matsushita,1;2 M. Kiuchi,2  T. Kiss,2

                                      H. Miao,3  H. Kitaguchi3  and H. Kumakura3
                  1Kyushu Institute of Technology, 680-4 Kawazu, Iizuka 820-8502, Japan

               2Kyushu University, 6-10-1 Hakozaki, Higashi-ku Fukuoka 812-8581, Japan

           3National Research Institute for Metals, 1-2-1 Sengen, Tsukuba 305-0047, Japan



    It  is  known  that  the  critical  current  density  in  Bi-2212  tapes  is  significantly  improved  by

introduction  of  pre-annealing  and  intermediate  rolling  (PAIR)  in  the  fabrication  process.   It  is

expected  that  the  crystalline  alignment  is  improved  also  in  the  region  apart  from  the  interface

to silver layer.  On the other hand,  the relatively low n value in Bi-based tapes is speculated to

be ascribed to a wide distribution of flux pinning strength caused by existing weak links.  In this

study the distribution of the flux pinning strength in a Bi-2212 tape prepared by PAIR process

is investigated by examining the scaling of the current-voltage characteristics.  The same analysis

is repeated for a tape prepared by a usual method.  The n value in the PAIR processed tape is

larger than in the usual tape.  The change in the distribution of the flux pinning strength due to

the PAIR process is discussed.